import React, { useState, useEffect } from 'react'
function Child({count}) {
  return (
    <div>{count}</div>
  )
}
export default function Memo() {
    const [n, setN] = useState(0)
    useEffect(() => {
        setInterval(()=>{
            setN(Math.random())
        },2000)
    }, [])
  return (
    <div>
        <Child count={2}></Child>
    </div>
  )
}
